diff --git a/src/vs/workbench/api/common/extHost.api.impl.ts b/src/vs/workbench/api/common/extHost.api.impl.ts
index 71ec5250fb9..cda268fcfeb 100644
--- a/src/vs/workbench/api/common/extHost.api.impl.ts
+++ b/src/vs/workbench/api/common/extHost.api.impl.ts
@@ -536,7 +536,7 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 				const interalSelector = typeConverters.LanguageSelector.from(selector);
 				let notebook: vscode.NotebookDocument | undefined;
 				if (targetsNotebooks(interalSelector)) {
-					notebook = extHostNotebook.notebookDocuments.find(value => Boolean(value.getCell(document.uri)))?.apiNotebook;
+					notebook = extHostNotebook.notebookDocuments.find(value => value.apiNotebook.getCells().find(c => c.document === document))?.apiNotebook;
 				}
 				return score(interalSelector, document.uri, document.languageId, true, notebook?.uri, notebook?.notebookType);
 			},
diff --git a/src/vs/workbench/api/common/extHostNotebookDocument.ts b/src/vs/workbench/api/common/extHostNotebookDocument.ts
index 2cc7a200edc..8f74a0a4b69 100644
--- a/src/vs/workbench/api/common/extHostNotebookDocument.ts
+++ b/src/vs/workbench/api/common/extHostNotebookDocument.ts
@@ -442,17 +442,7 @@ export class ExtHostNotebookDocument {
 		return this._cells[index];
 	}
 
-	getCell(cellHandle: number | URI): ExtHostCell | undefined {
-		if (URI.isUri(cellHandle)) {
-			const data = notebookCommon.CellUri.parse(cellHandle);
-			if (!data) {
-				return undefined;
-			}
-			if (data.notebook.toString() !== this.uri.toString()) {
-				return undefined;
-			}
-			cellHandle = data.handle;
-		}
+	getCell(cellHandle: number): ExtHostCell | undefined {
 		return this._cells.find(cell => cell.handle === cellHandle);
 	}